[78] Compare Ribot, La Psychologie des sentiments, p. 344.
[79] M. Bergson has a glimpse of the co-operation of “child’s fun” in our laughter, op. cit., p. 69; but he fails to see the magnitude of this factor.
[80] See The Emotions and the Will, “The Emotions,” chap. xiv., §§ 38–40.
[81] Cf. Dugas, op. cit., p. 128 ff.
[82] Wit and Humour, p. 7.
[83] See p. 76, ff.
[84] Prof. Groos does not, I think, bring out clearly enough the distinction here drawn, though he may be said to half-recognise it when he speaks of “joy in conquest” as the end of play combats (Play of Animals, pp. 291, 292).
[85] This restriction sometimes takes on a look of a conative process of self-control, e.g., when an older cat, not used to play, is importunately challenged by a lively kitten.
[86] On this “divided consciousness” in play see Groos, Play of Animals, p. 303 ff.
[87] On the uses of animal play see Groos, The Play of Man, Part III., sect. 2, and Lloyd Morgan, Animal Behaviour, chap, vi., sect. 2.